Brooding over brooders

Okay, it's like this...In April or May (depending on how long it takes hubby and I to build our coop) we'll be getting 6 chicks. I figure when they're little fuzzies I can rig up a heat lamp with a rubbermaid container topped with mesh to keep our cats at bay. (Can't keep them out of the garage altogether, as that's where we keep the cat boxes. Yea for kitty doors!)

I know, however, that chicks grow very quickly, and that they'll outgrow their rubbermaid digs absurdly quickly. Is it possible to move them to the house part of the coop, along with their heat lamp, as long as they stay confined inside? Will it be possible to keep the house warm enough, while still providing ventilation? My indoor part will be 4x6...is this too big to keep appropriately warm? Inside or out, what do I put on the floor? Doggy pee-pee pads, or will paper towels do?

Any advice would be greatly appreciated. I don't want to go to huge expense on the brooder, as we aren't going to be making chick purchases all that frequently. (or at least that's what we're saying right now...)
--Nikki

I think it will be fine. You are right in that they outgrow the plastic tubs quickly. However since you will only have 6 chicks, they can probably stay in the tub for maybe 3 weeks. I screwed a wood frame on the inside of my lids and cut away the plastic, then attached hardware cloth to the wood strips. The lids latch right back onto the tubs and I place my heatlamp on the wire.

It really doesn't matter how large the inside part of the coop is as long as the chicks can get under the heatlamp for warmth and move away it too warm.